bug#68487: [PATCH] Make jump commands usable for all skeletons

[martin <law@martinmarshall.com>]

Eli Zaretskii <eliz@gnu.org> writes:

> Ping!  Martin, can you please respond to Stefan's comments, so we
> could move forward with this issue?

Sorry for the long delay in responding.  I'll try to get to this by the
end of the weekend.


>> Cc: 68487@debbugs.gnu.org
>> Date: Sat, 02 Mar 2024 23:07:18 -0500
>> From:  Stefan Monnier via "Bug reports for GNU Emacs,
>>  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
>> 
>> >> Ideally this should go along with the removal of the use of a vector in
>> >> `expand-list`, which not only is odd given its name but is odd because
>> >> it seems completely useless.
>> >
>> > Nothing (at least nothing in Emacs core) stores a vector to
>> > `expand-list`.  So I'm curious why `expand-abbrev-hook` was written to
>> > account for that possibility.
>> 
>> It's because it internally did that, tho I don't know why it did that
>> internally since my patch seems to show that it's simpler not to.
>> 
>> > Changing `expand-abbrev-hook` to expect `expand-list` to actually be a
>> > list (as you did with your patch) makes sense to me.
>> 
>> Should I install it, so it's kept separate from the changes you add
>> on top (mostly for readability of the patches)?
>> 
>> > What do you think?
>> 
>> I find the patch a bit hard to read, maybe for lack of a separate
>> description of the intended changes, or maybe because it does too much
>> in a single step.
>> 
>> I have one question, tho:
>> 
>> >  (defun expand-do-expansion ()
>> > -  (delete-char (- (length last-abbrev-text)))
>> > -  (let* ((vect (symbol-value last-abbrev))
>> > -	 (text (aref vect 0))
>> > -	 (position (aref vect 1))
>> > -	 (jump-args (aref vect 2))
>> > -	 (hook (aref vect 3)))
>> > -    (cond (text
>> > -	   (insert text)
>> > -	   (setq expand-point (point))))
>> > -    (if jump-args
>> > -        (funcall #'expand-build-list (car jump-args) (cdr jump-args)))
>> > -    (if position
>> > -	(backward-char position))
>> > -    (if hook
>> > -	(funcall hook))
>> > -    t))
>> > -
>> > -(defun expand-abbrev-from-expand (word)
>> > -  "Test if an abbrev has a hook."
>> > -  (or
>> > -   (and (intern-soft word local-abbrev-table)
>> > -	(symbol-function (intern-soft word local-abbrev-table)))
>> > -   (and (intern-soft word global-abbrev-table)
>> > -	(symbol-function (intern-soft word global-abbrev-table)))))
>> > -
>> > -(defun expand-previous-word ()
>> > -  "Return the previous word."
>> > -  (save-excursion
>> > -    (let ((p (point)))
>> > -      (backward-word 1)
>> > -      (buffer-substring p (point)))))
>> > +  ;; expand-point tells us if we have inserted the text
>> > +  ;; ourself or if it is the hook which has done the job.
>> > +  (if (listp expand-list)
>> > +      (setq expand-index 0
>> > +	    expand-pos (expand-list-to-markers expand-list)
>> > +	    expand-list nil))
>> > +  (run-hooks 'expand-expand-hook))
>> 
>> Hmm... but this `expand-do-expansion` doesn't actually "do" any
>> expansion any more, right?
>> 
>> >  (defun expand-skeleton-end-hook ()
>> > -  (if skeleton-positions
>> > -      (setq expand-list skeleton-positions)))
>> > +  (when skeleton-positions
>> > +    (setq expand-list skeleton-positions)
>> > +    (expand-do-expansion)))
>> 
>> Here if you read the code out loud it doesn't make sense to call 
>> `expand-do-expansion` since skeleton has already "done the expansion".
>> 
>> 
>>         Stefan
>> 
>> 
>> 
>> 
>> 

-- 
Best regards,
Martin Marshall